Process of manufacturing filtering material.



rATE

ATEN

GEORGE ALFRED ABBOTT, OF BURNLEY, VICTORIA.

SPECIFICATION forming part of Letters Patent No. 651,474, dated June 12,1900.

T0 rtZZ whont it may concern.-

Be it. known that I, GEORGE ALFRED AB- BOTT, a subject of the Queen ofGreat Britain, and a resident of 53 Bendigo street, Bu rnley, in theColony of Victoria, have invented a certain newand useful FilteringMaterial and Method or Process of Manufacturing Same, of which thefollowing is a specification.

This invention has been devised to provide an efficient and economicalfilter medium or material and one which when dirtied by use may beeasily cleaned either by washing or by heat; and it consists in theemployment of a composition of materials and the method or process bywhich the component parts are associated together and afterward treatedin order to produce the filtering material.

I shall now describe the materials used by me and the way in which theyare treated.

I take clay (either red or white in color) and exercise special carethat it is free of foreign matter, especially limestone. This clay iswashed with clean Water, so as to produce a pasty result, free fromlumps of any kind. This clay paste is then dried until it hardens byexposure to the air or by evaporation in a heated appliance. The dryresult is then ground in any approved grinding appliance to animpalpable powder resembling flour. I then take a quantity of selectednon-bituminous lignite, and after drying same I grind it in any approvedpulverizer into a powder 7 which will pass through a gauze of aboutthree hundred and fifty perforations to the square inch. It isabsolutely necessary that the lignite'must be non-bituminous and that itwill not vitrify by heat. I then mix sixtyfive parts, by bulk, of thefinely-powdered clay with thirty-five parts, by bulk, of the siftednon-bituminous lignite, thoroughly associate these materials with oneanother in any approved mixing-machine, and add sufficient water theretoto form a stiff paste. It

is preferable that the mixing action should be continued for some timeafter the water has been added to the parts before described and untilit may be fairly assumed that the non-bituminous lignite has beenequally disseminated throughout the clay. The stiff paste thus producedis then shaped on a potters wheel into plates or blocks of the requiredshape and thickness to fit the filteringmachine in which my material isto be employed. The plate or block is then removed from the potterswheel, partially dried, and placed under a press and a pressure ofpreferably about four and one-half tons persuperficial square inchimposed upon it. The plate or block is then carefully, evenly, andslowly dried, conveyed to a potters kiln, slowly heated therein, and thetemperature raised until the plates are brought to a white heat. Duringthe burning the fine particles of the non-bituminous lignite entirelydisappear and leave small interstices in their place, in which aninfinitesimal quantity of ash remains, with no vitrifying effect.

I have found by experiment that the use of other than non-bituminouslignite produces a vitreous remnant or coating which is impervious tothe passage of Water, and therefore practically useless as a filtermaterial.

If the kiln has been allowed to cool down, the plates will be found tobe of a uniform porosity and the minute interstices throughout thematerial will be such as to allow a passage of water through thematerial, but small enough to prevent any bacilli, microbe, foreign orsolid matter to pass through.

I find by practice that when my filtering material (manufacturedasherein mentioned) is used a quantity of organic and solid mattersdeposited by the water under filtration is left upon the outer side ofthe filter-plate and that such refuse may be freely removed by washingwith either hot or cold water, or the filterplate may be placed in anyclean household fire and burned to a red heat, so as tocompletelydestroy any remnant of such matters. It will thus be seen thatthe filtration properties of my material are indefinitely preserved. Thenon bituminous non-Vitrifying lignite may be obtained in the Colony ofVictoria, Australia.

Having now particularly described and ascertained the nature of my saidinvention and in what manner the same is to'be performed, I declare thatwhat I claim is-- 1. A filtering material compounded from a mixture ofpulverized clay With pulverized non-bituminous non-vitrifying ligniteincorporated together and burned substantially as and for the purposesset forth.

2. A filtering material compounded from a mixture of about sixty-fiveparts by bulk offrom to pressure, slowly drying the pasty material, andthen placing itina kiln and slowly raising the temperature to a whiteheat, substantially as and for the purposes set forth.

Signed at Melbourne, in the Colony of Viotoria, this 8th day of May,1899.

GEORGE ALFRED ABBOTT.

\Vitnesses:

A. O. SAoHsE, A. HARKER.

